Midgut immune responses induced by bacterial infection in the silkworm, Bombyx mori

Insect gut epithelial cells produce reactive oxygen species （ROS） and antimicrobial peptides （AMPs） to protect hosts from pathogenic microorganisms. In this study, we evaluate the pathogenicity of Pseudomonas aeruginosa and Bacillus bombysepticus in the silkworm, Bombyx mori. Survival curves show that B. bombysepticus is deadly when larval silkworms are infected orally. Bacterial infection caused intestinal hydrogen peroxide （H202） and nitric oxide （NO） levels to increase significantly by 8 and 16 h post-infection （hpi）, respectively. Real-time quantitative polymerase chain reaction （qPCR） analysis shows that the transcription levels of dual oxidase （Duox） and catalase （CAT） are highly up-regulated by P. aeruginosa infection at 8 hpi. P. aeruginosa infection induced nitric oxide synthase 2 （NOS2） expression at 16 hpi, which contributes to the generation of NO. mRNA levels of AMP genes, specifically Glovorin 2 and Glovorin 3, which obviously increase during the eady infection stage. These results indicate that invading bacteria ele.vate intestinal ROS and NO levels and induce AMP gene transcription, which contributes to intestinal immune defense.

Identification of two clip domain serine proteases involved in the pea aphid's defense against bacterial and fungal infection

Phenoloxidases(POs)are required for the pea aphid s defense against bacterial and fungal infection.Prophenoloxidases(PPOs)are protcolytically converted to its active form PO through a clip domain serine protease cascade.In this study,we identified five clip domain serine proteases in the pea aphids.The messenger RNA levels of two of them,Ap.SPLP and Ap_VP,were upregulated by Gram-positive bacterium Staphylococcus aureus and fungus Beauveha bassiana infections.Double-stranded RNA-based expression knockdown of these two genes resulted in reduced PO activity of the aphid hemolymph,higher loads of S.aureus and B.bassiana in the aphids,and lower survival rates of the aphids after infections.Our data suggest that Ap.SPLP and Ap_VP are involved in PPO activation pathway in the pea aphid.

Protection of Shengmai Recipe on Improving Cardiac Function and Attenuating Kidney Injury in Pressure Overload Rats

Objective Shengmai Recipe （SMR） is a Chinese patent medicine used for the treatment of chronic heart disease. In order to further assess the renal-protective effect against ischemia lesion of SMR, the cardioprotective effect of SMR on pressure overload-induced left ventricular （LV） systolic dysfunction and the potential mechanism on alleviating myocardial damage, myocardial fibrosis, and renal ischemia lesion in chronic heart failure （CHF） rats were investigated. Methods Rats with partially ligated abdominal aorta were randomly divided into model, Sham, and SMR groups. One week after recovery from surgery, animals were preventively ig administered with SMR at the dose of 810 mg/kg once daily for 8 weeks. Cardiac function and structure, endogenous biomarkers （CK-MB and LDH）, myocardial fibrosis, and organ pathological change were estimated by echocardiography, immunodepression and velocity method, hematoxylin- eosin staining, and masson＇s trichrome staining, respectively. Results The administration of SMR significantly decreased serum CK-MB and LDH levels and reduced myocardial fibrosis. Interestingly, SMR not only improved cardiac function but also ameliorated kidney injury induced by ischemia in CHF rats. Conclusion SMR could enhance the LV contractile function, reduce myocardial necrosis, and reverse LV remodeling in CHF rats, and most importantly, SMR could be used to treat the renal ischemia injury in pressure overload rats.